1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus and, particularly, relates to an ink jet type recording head which ejects ink as liquid and an ink jet type recording apparatus.
2. Related Art
An ink jet type recording head which includes a head main body in which a pressure generation chamber communicating with a nozzle opening through which ink droplets are discharged is deformed by a pressure generation unit, such as a piezoelectric element, in such a manner that an ink droplet is discharged through the nozzle opening and a flow-path member which constitutes a flow path of ink supplied to the head main body is known as a liquid ejecting head.
The head main body is connected to the flow-path member. Ink is supplied from the flow path to the head main body or ink is discharged from the head main body to the flow path. An ink jet type recording head in which a plurality of nozzle opening groups, each of which is constituted of a plurality of nozzle openings and ejects the same ink, are provided in one head main body and a flow-path member having a plurality of flow paths through which different inks are supplied to respective nozzle opening groups are provided has been proposed (see JP-A-2005-193680, for example).
In the ink jet type recording head according to JP-A-2005-193680, a manifold in common to the nozzle openings constituting the nozzle opening group is formed. A plurality of manifolds are provided corresponding to the number of the nozzle opening groups. The plurality of manifolds are arranged in a state where the manifolds overlap in a direction perpendicular to a liquid ejection surface in which the nozzle openings are provided. Accordingly, the plane-direction size of the liquid ejection surface can be reduced, compared to in the case where all of the manifolds are arranged in the same plane.
However, when the plurality of manifolds overlap each other in the direction perpendicular to the liquid ejection surface, the plurality of manifolds are located at different positions in the direction perpendicular to the liquid ejection surface. As a result, the position of each manifold in relation to the liquid ejection surface is different for each nozzle opening group. Furthermore, the length of a flow path from the manifold to the nozzle opening group is different for each nozzle opening group, and thus flow-path resistance is different. Furthermore, the weight of ink droplets ejected from the nozzle opening group is different for each nozzle opening group.
When the plurality of manifolds are located at different positions in the direction perpendicular to the liquid ejection surface, as described above, variation in ejection properties of the ink ejected from each manifold occurs.
Such a problem is not limited to an ink jet type recording head which discharges ink but is shared by a liquid ejecting head and a liquid ejecting apparatus which eject liquid other than ink.